Global warming -- you may accept or reject those who say it is a dangerous phenomenon. But if the planet is warming, and humanity is contributing to it, shouldn't someone be thinking about solutions?

If the Earth is, in fact, engaged in a long-term warming cycle -- and if humanity is partly responsible -- can it be reversed?

Scientist Richard Somerville of the Scripps Institution of Oceanography believes it can be. "Yes, but not overnight. The way to reverse it is to reduce the emission of CO2 (Carbon Dioxide) into the atmosphere. One thing you can do is capture the CO2 as its emitted, and sequester it. The other is to reduce your dependence on fossil fuels."

Possible solutions to global warming range from the simple to the complex -- from changing a light bulb to engineering giant reflectors in space. The most talked about solutions involve expanded use of alternative energy technologies, and less reliance on fossil fuels.

Climate scientist Michael MacCracken says society has to make the commitment to change. "You have to commit to taking actions that will require society to do certain things, but many of those can be beneficial and helpful, but we're going to have to change the path that we are on and how we get energy."

Some scientists believe global warming is part of a natural cycle and will take care of itself.

Public policy researcher Myron Ebell of the Competitive Enterprise Institute issues a caution. "There will be some negative consequences or impacts, and there will be some positive ones. I don't think either one, either the negative or the positive will be particularly pronounced or extreme or severe."

Richard Somerville of the Scripps Institution of Oceanography says, "That seems very unlikely. Science doesn't give you certainties. Science gives you likelihood, but we think that it's likely that climate warming of the last few decades isn't due to the usual causes -- changes in the Earth's orbit, changes in the sun, volcanoes, but it's due primarily to humans adding greenhouse gases to the atmosphere."

Public policy expert Myron Ebell says, "We know that there is a lot of natural variability in the climate. We know that people in some regions of the world at various times have lived with climates that are much warmer and much cooler than now and all the historic evidence is that they somehow managed to survive that."

John Topping of the nonprofit Climate Institute says it will be private industry -- not governments -- coming up with solutions. "We need to get investment flows going in the direction of emerging clean energy technologies. Part of that's going to happen because we, as consumers, step forward and we are conscious in our buying habits to get more energy-efficient products."

Higher gas prices are making fuel-efficient vehicles more attractive to consumers. Building and home constructions are becoming more energy efficient.

Topping says for individuals, industries and nations dealing with climate change is a matter of thinking smart. "Climate change is a huge challenge. But climate change also provides an opportunity for countries to really further themselves, and that's the only way we're going to advance much globally, is to look at approaches that protect the environment at the same time that they promote equitable economic growth."

Topping says Iceland is a good example. "About 50 years ago, they were a huge importer of coal from abroad and relatively poor, but they realized if they could use the geothermal for heating, they could convert their energy system for electricity mostly to renewables. Iceland now has the sixth highest per capita income in the world."

Wider application of renewable energy resources could reduce greenhouse gases and offset global warming. Some scientists are suggesting grander solutions, involving rearranging Earth's environment; building huge sunshades in space, for example, tinkering with clouds to make them reflect more sunlight, perhaps tricking oceans into soaking up more heat-trapping gases.

Climate scientist Michael MacCracken recommends first steps. "There are a host of things to do first. Many different technologies that are cost effective right now. What we need to do is do as many and all of them as we can before we get into these geoengineering technologies that basically only serve to continue our addiction to fossil fuels."

Richard Somerville of the Scripps Institution of Oceanography sums up the search for global warming solutions this way: "We need to waste far less energy than the energy we waste now. Furthermore, it has to be a global effort."